Holiday Rambler in tank fuel pump quit. Cant find relay?

https://big.nyc3.cdn.digitaloceanspaces.com/revgroup/general/2004_Neptune.pdf?mtime=20201116123133&focal=none

Page 322 Doug

I do not know the chassis but I do know Workhorse. And GM in general.

On a workhorse front and center.. open the hood and if like me you are six foot. Directly in front (Center) is a black plastic box.. It's in there

On my 1992 Lumina the relays were on the top front rail (Radiator mount rail) passanger side. and it's one of them.

Generally relays are all "Grouped"

Never had a fuel pump relay fail
Did have the starter pilot relay fail (Yup right next door) fixed it (Actually fixed the relay... .Yup I know how to do that).

Horn relay is there too.
HEVAC blower.. Same spot.

Join the group monacoers.org it is a group dedicated to all older Monaco products. There is a wealth of information on the group.

Thanks but not a GM. Its a pusher rear engine with a cummins diesel.
No hood. Small fuse box in rear lower battery cabinet and large fusebox in outside cabinet below drivers window.
Fuses and relays labeled but none labeled as fuel pump so kind of stumped.
Just learned Monaco/Holiday Rambler lost all pre 2011 records, diagrams and schematics in a fire darn it, so on my own it appears.

Thanks for link to manual so have digital and hard copy now. No mention of auxiliary fuel pump in manual though.
Should be able to trace leads somewhere if lucky but many wires bundled together down the frame.

Thanks Doug, but no fuel pump reference on page 322 I can see?
Do you see something im missing?

Also thanks to poster for Monaco group link!

The Cummins engine has a 12V fuel lift pump on the engine ...didn’t find a pump in the tank on page 397.

Are you sure it has a fuel pump in the tank? My Windsor doesn't have that, it
has an electric fuel lift pump mounted on the engine. I can hear it run for
a while when I turn the ignition on.

What sort of trouble are you having?

The 300 cummins starts and idles fine. Goes into high idle fine and even revs if not under load. Once in gear with brake set or driving it will stumble, rebound and then stumble again in a cycling way like running out of fuel.

My diesel mechanics scan tool shows no fuel pressure from any aux fuel pump, but it does show vac. pressure from hi pressure pump drawing fuel to the engine. Dont know for certain there is an aux pump, but assuming there is because tank is over 20 feet from the engine and seems should be one. Manual makes no mention of one tho?
On top of tank there are number of wires going thru a portal into the tank and seems like more than needed for sending unit.
Two good diesel mechanics believe Cumminns ISB300 engines have an aux pump, but could they be wrong?
Manual does mention that clogged tank vent can give issues and guess id better check it out, but didnt ghink could be culprit.

Hoping might be some good techs on the Monaco group provuded me, but busy next couple days. Thanks much for replies and advice.

Broncorambler wrote:
The 300 cummins starts and idles fine. Goes into high idle fine and even revs if not under load. Once in gear with brake set or driving it will stumble, rebound and then stumble again in a cycling way like running out of fuel.

My diesel mechanics scan tool shows no fuel pressure from any aux fuel pump, but it does show vac. pressure from hi pressure pump drawing fuel to the engine. Dont know for certain there is an aux pump, but assuming there is because tank is over 20 feet from the engine and seems should be one. Manual makes no mention of one tho?
On top of tank there are number of wires going thru a portal into the tank and seems like more than needed for sending unit.
Two good diesel mechanics believe Cumminns ISB300 engines have an aux pump, but could they be wrong?
Manual does mention that clogged tank vent can give issues and guess id better check it out, but didnt ghink could be culprit.

Hoping might be some good techs on the Monaco group provuded me, but busy next couple days. Thanks much for replies and advice.

On the Manual I sent you the link to. Go to the Calibrating part of the Fuel tank sending unit. You will see WHY there are more wires than you think is necessary. I was waiting for others to reply. I NEVER saw any In tank fuel pump on a Roadmaster Chassis. The fuel pick up and return is just 4 hoses. The 3rd/4th hose is for the optional Aqua Hot and Genset feeds. The good news is, since the Fuel pump system is part of Cummins, you should be able to get it fixed by a Cummins Service Center. Doug